While many farmers in the Midwest languish in dust-bowl conditions, Dennis Atkinson's almonds are as plump as peach pits. Mr. Atkinson, who oversees orchard operations for the Tejon Farming Company here, doesn't worry about rain. A 50-foot-wide sluice on one edge of the farm, through a system of pipes and pumps, waters the 26,000 acres of nuts, grapes, and other crops.

The worst drought in a half century has left many farmers in the Midwest and Mid-Atlantic states with stunted crops while others, some in the same regions, prepare for or have reaped healthy harvests - and profits.

Rain, of course, is the greatest unequalizer. But irrigation has also helped some survive an otherwise devastating dry spell.

``It would be a disaster if we didn't have irrigation,'' says Mr. Atkinson, sitting in an air-conditioned office on a day when the temperature here, on the southern edge of the vast Central Valley, California's green thumb, will hit 106 degrees F.

Even in the Midwest fortunes have varied. Hardest hit by the drought have been parts of the eastern cornbelt (Illinois, Indiana, Ohio, Michigan) and northern plains (the Dakotas and Minnesota). But portions of Iowa, Nebraska, Kansas, and Oklahoma have received some rain. Recent cloudbursts have also brought a modicum of relief to areas of the Ohio River Valley (Kentucky and southern Ohio).

Within many of these areas, farmers have offset nature's miserliness by man-made means. In Nebraska, where some 75 percent of the farms are irrigated, growers in the central and western part of the state tap into the Ogallala aquifer, a massive subterranean reservoir. In Colorado, there was enough of a snowpack last winter to fill the state's reservoirs and allow farmers to siphon off needed supplies.

While pumping is expensive, this year many of the costs have been offset by higher crop prices, driven up by drought-induced shortages.

``Irrigation this year is certainly going to pay off,'' says Leo Holthaus with the field office of the Federal Crop Insurance Corporation in Lincoln, Neb.

The drought has revived an enduring debate over irrigation. Currently some 13 percent of America's cropland is irrigated. But most specialists don't expect to see any major shift in the numbers. The reason is the cost.

``Can you afford to have the equipment for something you may need only once every four or five years?'' asks Ross Korves, an American Farm Bureau Federation economist.

Those farmers hurt the most will be the ones least able to afford anything new. ``About the only thing they've got are prayers,'' says James Ells, a crop specialist at Colorado State University.

Among the states least affected by the drought is California, the nation's No. 1 agricultural producer. Although the state is in the second year of a dry spell, irrigation over more than 90 percent of its farm land has put it in position for a good harvest this year.

Experts warn that a third dry year could imperil the state's farmers, since there wouldn't be enough water in wells or reservoirs to supply the massive irrigation system.

Cattlemen have already been pinched. Many rely on rainfall to green pasture land and thus have been forced to ship livestock out of state for fattening, buy expensive feed supplements, or send steers to market early.

Yet most farmers are doing well. The Bank of America estimates that gross farm income in the state will reach $16.1 billion this year, up 2 percent from 1987.

``We are going to get by fairly well this year,'' says Clark Biggs of the California Farm Bureau Federation.

Wheat and corn farmers have been particularly fortunate. They are reaping large profits from the higher prices being paid for the food stuffs.

Tejon Ranch Corporation, parent of Tejon Farming, has seen one other modest benefit: higher prices for almond husks, the fuzzy sheaths that surround the nut and look like velour clams. Ranchers use them for cattle feed.

The farm here south of Bakersfield, where oil pumps bob in the fields next to almond groves, is expecting an above-normal harvest for most of its crops, which include walnuts, pistachios, grapes, and various row crops.

``We like a good snowpack and a little rain in the winter'' to replenish reservoirs, Tejon's Atkinson says. ``The rest is just a nuisance.''